Sunday, September 06, 2009

Where does Rodney Rank Among Tigers Relievers?

Fernando Rodney has been one of the most pleasant surprises on the Tigers and a key to the team's first place standing in the American League Central division this season. In fact, his 3.28 Win Probability Added (WPA) ranks third in the American League behind Mariano Rivera and Jonathan Papelbon.

The WPA statistic attempts to measure a reliever's contribution to his team's victories by determining how each batter the pitcher faced altered the outcome of the game. For example, a reliever who enters a game with a one run lead in the ninth inning and retires the side will contribute more to a win than a pitcher who comes in with a nine run lead and retires the side. For more information on the calculation of WPA, see this earlier post. The WPA statistic can be found at Fan Graphs for all players back to 1974.

How has Rodney's season ranked among Tigers relievers since 1974? The top 15 WPAs for Tigers relievers are shown in the table below. Rodney is eighth on the list and the best since Joel Zumaya in 2006.

The rest of list is filled with pitchers who conjure up some good memories. Not surprisingly the top WPA was achieved by Willie Hernandez in his MVP and Cy Young award winning 1984 season. Hernandez saved 32 games in 33 innings and compiled a 1.92 ERA but what made him stand out the most was his 140 1/3 innings pitched. He is a good example of how the closer role has changed in the last few decades. The following pitchers appeared multiple times on the list: Auerilio Lopez (1979, 1980, 1983), Mike Henneman (1987, 1990, 1991), Todd Jones (1997, 2000) and Doug Brocail (1998, 1999).